The suicide bomber deliberately chose the place where he could cause “maximum carnage” when he detonated a bomb at a pop concert in Manchester, she said.

May said “many” children and young people were among the 22 dead and 59 injured in the attack.

Georgina Callander has been identified as one of 21 people killed.

The West Australian

VideoGeorgina Callander has been identified as one of 21 people killed.

Teenage screams filled the arena just after the explosion Monday night, which Ms May said was “a callous terrorist attack.”

“We struggle to comprehend the warped and twisted mind that sees a room packed with young children not as a scene to cherish but as an opportunity for carnage,” she said.

“All acts of terrorism are cowardly ... but this attack stands out for its appalling sickening cowardice, deliberately targeting innocent, defenceless children and young people who should have been enjoying one of the most memorable nights of their lives.”

Camera IconConcertgoers are seen running through Manchester Victoria station after an explosion at Manchester Arena.Picture: AP

After chairing a meeting of the Government’s Cobra emergency committee, May condemned the “cowardice” of the attacker and hailed those who rushed to help, who had shown “the spirit of Britain ... a spirit that through years of conflict and terrorism has never been broken and will never be broken”.

She vowed: “The terrorists will never win and our values, our country and our way of life will always prevail.”